A vaccine is on the way, but some Latin American countries will have to wait longer than others

By Angélica Serrano-Román | Six Feet Forward

While a newly authorized Covid-19 vaccine is on its way to be administered to the people at most risk of contracting the virus, some countries are uncertain about when they could vaccinate their population.

Central American countries like Guatemala are not considering the Pfizer-BioNTech vaccine and Moderna’s shot because of its storage and distribution requirements, as well as the cost per dose.

“These two vaccines (Pfizer-BioNTech and Moderna’s) are not part of our candidates due to the freezing requirements we would need to distribute them. But we expect new data in the next month from Oxford-AstraZeneca’s vaccine, which could be soon authorized,” said Dr. Edwin Asturias, director of Guatemala’s CopreCovid, the virus response commission.

Some members of COVAX —an alliance of 172 countries promoted by the World Health Organization to have access to the vaccine as soon as it is authorized— would also have to wait longer due to the infrastructure challenges of the Pfizer-BioNTech shots.

AstraZeneca’s vaccine candidate, developed with Oxford University, has become one of the primary options for those countries.

Guatemalan Congress has budgeted 400 million Quetzals (approximately $51.2 million) to acquire AstraZeneca’s vaccine in 2021 — but hasn’t disbursed the funds. 

Through COVAX, at least 3.3 million Guatemalans could get the vaccine, Asturias said.

AstraZeneca’s vaccine is 70.4% effective at preventing symptomatic Covid-19 after receiving two doses, concluded an interim analysis conducted by Oxford University. In one of its shots, it showed an efficacy rate of 90%.

The U.K. vaccine candidate can be stored, transported and handled at 2-8°C, which are normal refrigerated conditions, for six months. Meanwhile, the Pfizer-BioNTech vaccine showed 95% efficacy 28 days after the first dose. However, shots must be stored at -70°C for up to 10 days unopened.

Following the Emergency Use Authorization issued by the U.S. Food and Drug Administration (FDA) of the Pfizer-BioNTech vaccine, the first limited release will be administered to healthcare workers and people in long-term care facilities. At the moment, it will be used only on people over 16 years of age.

Mexico also signed multiple agreements with pharmaceutical companies based in the U.K. and China to guarantee a Covid-19 vaccine soon.

Mexican authorities expect around 77.4 million AstraZeneca’s shots. Before the FDA’s authorization, the government had already agreed to buy 34.5 million doses of the Pfizer-BioNTech vaccine. 

Pfizer gained ground in countries such as Mexico and Peru after agreeing to store, transport and vaccinate the population. Others like Chile are having discussions with Pfizer, but keeping alliances with COVAX.

Still, countries must achieve one crucial goal: to vaccinate most of the population to reach herd immunity.

“The real challenge is a democratic distribution of the vaccine. To achieve widespread protection, between 70% to 80% of the population must be vaccinated. An epidemiological study must be carried out to find out the most affected sectors and who has priority,” said Dr. Gerardo Cervantes, Chief of Epidemiology at the Hospital Mac San Miguel de Allende, in Guanajuato, Mexico.

It is expected that private hospitals and health clinics will demand more Pfizer-BioNTech vaccines compared to the public sector, Cervantes said.

“The vaccine will help us control the pandemic in the short or medium term, but we do not know how long it will give us immunity. The mRNA technology used for the Pfizer and Moderna vaccine is very new. It is pioneering,” the epidemiologist added.

Marcelo Ebrard, Secretary of Foreign Affairs of Mexico, also announced on Dec. 9 that the government agreed with China-based CanSino Biologics Inc. and LATAM Pharma Innovative Ventures to receive 35 million doses of the vaccine. “More options are available for Mexico,” he wrote.

China’s first patented vaccine is single-dose and remains stable between 2-8°C, making it easier to store and transport, CanSino Biologics said. However, it is currently undergoing late-stage trials involving more than 40,000 volunteers. 

The shot uses the replication-defective adenovirus type 5 as the vector to express the SARS-CoV-2 spike protein. 

Although Peru signed an agreement with COVAX to receive 13.2 million doses and paid $21 million in advance, it also agreed to obtain vaccines from Pfizer-BioNTech.

Through a bilateral negotiation with Pfizer-BioNTech, Peru agreed to pay $118.8 million for 9.9 million doses.

Minister Mazzetti Soler said the company promised to maintain the required thermal conditions until the vaccination. But the Peruvian government will acquire freezers and other special equipment as a contingency plan, she said.

“Even with vaccines that have been authorized, there is not enough supply,” Dr. Mónica Feliú-Mójer, an expert in neurobiology and scientific communication, said.

Feliú-Mójer also pointed out that countries like Guatemala and Puerto Rico have other challenges than the vaccine’s cost: infrastructure problems. “In order to store the vaccine, you must have a power backup in case of a blackout, for example.”

On Tuesday, the government of Puerto Rico began the distribution of the Pfizer-BioNTech vaccine in 65 hospitals around the island. The federal government will cover expenses related to the vaccination, Gov. Wanda Vázquez said.

As the island faces infrastructure and temperature challenges, the U.S. National Guard assured it has at least five refrigerators for the first vaccine batch, according to Adjutant General of Puerto Rico, Major General José Reyes. 

The National Guard will be in charge of the vaccine distribution, while chains like Walgreens and CVS will vaccinate in long-term care center facilities.